250r motorheads?

[barbwire44]

I would like to know how to tell the difference between the 88 and 86 cylinders? I have an 88 250r with an 86 cylinder and spacer plate now but i have an extra jug i want to get bored and ready to install, I just dont know what year the cylinder is so I get the right piston.
thanx

[beerock]

you need a 86 piston regardless of cyllinder year if you are using the spacer plate.(the wrist pin placement is 5mm lower on the 86)
If you use a 87-89 piston the engine will not start with the spacer plate, it will without it though.

oh and the 86 cylinder doesnt have a bridged intake.

[barbwire44]

Hey thanks man, I also found another way to distinguish the difference is on the bottom of the sleeve the year is stamped in it. I am going to remove the spacer plate and put the 88 jug back on with an 1988 pro-x piston. Also the cylinder has been ported and im not sure who did it on the side of the cylinder it has TWR III engraved in it? Any ideas?:cool:

[beerock]

not sure who did the porting
if you do go to the 88 pitson the motor is gonna be more abrupt and it wont top out as far as it would with the spacer.

but might as well give it a try, and then next rebuild you can decide which way you like better.
I have the 88 piston now.
and I am switching to the 86piston/spacer/88rod